Remove Immutable File Attribute - Auditd — Sigma Rule

Rule metadata and linked tags

Author: Jakob Weinzettl, oscd.community. Source status: test; severity: medium. Source dates: 2019-09-23 / 2022-11-26.

{
  "product": "linux",
  "service": "auditd"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: af06d645c3ae68cd20491f379a8595a54db98792ab29cd0ed217d3ca8e4d8f9c

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Remove Immutable File Attribute - Auditd
id: a5b977d6-8a81-4475-91b9-49dbfcd941f7
status: test
description: Detects removing immutable file attribute.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1222.002/T1222.002.md
author: Jakob Weinzettl, oscd.community
date: 2019-09-23
modified: 2022-11-26
tags:
    - attack.defense-impairment
    - attack.t1222.002
logsource:
    product: linux
    service: auditd
detection:
    selection:
        type: 'EXECVE'
        a0|contains: 'chattr'
        a1|contains: '-i'
    condition: selection
falsepositives:
    - Administrator interacting with immutable files (e.g. for instance backups).
level: medium
simulation:
    - type: atomic-red-team
      name: Remove immutable file attribute
      technique: T1222.002
      atomic_guid: e7469fe2-ad41-4382-8965-99b94dd3c13f

Original YAML and metadata in JSON

False positives

• Administrator interacting with immutable files (e.g. for instance backups).

Source references

• https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1222.002/T1222.002.md